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MORPHOLOGICAL, HISTOPATHOLOGICAL AND MOLECULAR CHARACTERIZATION OF MYXOSPORIDIA AND COCCIDEA PARASITES IN Pygocentrus nattereri Kner, 1858, FROM THE MUNICIPALITY OF PRACUÚBA, IN AMAPÁ

Amazon; Pygocentrus nattereri; Myxozoans.

The Brazilian Amazon has the largest freshwater hydrographic basin in the world, and with this
it also has a great diversity of fish, with an estimated richness of between 1.5 and 6 thousand
species. In this sense, the region has great fishing potential and is one of the main economic
activities developed in the north of Brazil, especially in the state of Amapá, the third largest
regional representative and its privileged geographical location. Another aspect is the high
consumption of fish by riverside communities, who on average eat 369g/day per person. In
view of this, fish are sensitive to environmental changes, which can be caused by anthropogenic
or natural actions, causing ecological imbalance and the proliferation of various parasites,
including myxosporidia and coccidia.These cause a series of diseases in fish, resulting in their
death and making them unsuitable for human consumption, and some parasites have already
been described with zoonotic characteristics. The aim of this study was to describe the
morphological aspects and phylogenetic relationships of microparasites from Pygocentrus
nattereri, caught in the Sacaizal lake in the municipality of Pracuúba, in the state of Amapá.
The specimens were transported dead to the Aquatic Organism Health Research Laboratory at
the Federal Rural University of Amazonia (UFRA), where they will be necropsied. Using a
stereomicroscope, the specimens will be examined for cysts and/or tissue fragments with signs
of parasitism, which will be confirmed using fresh slides viewed under an optical
microscope.The samples will be fixed and processed for histology, molecular biology and
scanning electron microscopy. Preliminary analyses showed the presence of mature spores of
cnidarians belonging to the class Myxozoa, with morphology belonging to the genera
Henneguya sp in the gill filament, Calyptospora sp in the liver and Myxobolus sp in the liver,
spleen, kidneys and gill filament. These studies contribute to our knowledge of the parasites
that affect fish in the Amazon region.